I am terribly sorry you have to go through this Niki. You have to do what you feel is right, do not make any rash decisions right now, take time breathe and just relax. You can and will get through this I know it seems tough but you are a smart/tough girl you are just emotional right now.
Do not under any circumstances get back with him if he would come to his senses and realize what he is missing. If he is leaving you now at the time you need him the most he will most likely do it again.
If you really feel adoption is the best choice then just pick up some pamphlets and read up on it before you decide. I watched an episode of 16 and pregnant, where the couple got to decide whom to give their baby to and meet with them and everything.
I wish I lived closer and could be there for you. I feel your aloneness.I know how you feel about not having any friends. I always had my mom there for me, she is my best friend and we do everything together, but she is not going to be here much longer. I do talk to people at my work , but that is as far as it goes i liked just having my mom and hubby.
I wish you all the best and if you need to vent I have a good ear.
Brandy